The document discusses stars and constellations. It defines a star as a celestial object that emits heat and light through nuclear fusion reactions in its core. Constellations are groups of stars that appear to form patterns in the night sky. The document outlines different types of stars based on characteristics like size, color, temperature and composition. It also provides details about some specific constellations like Orion, Hydra and Crux.
7. Sun is only about 150 million
kilometers away and it takes only 8
minutes and 20 seconds for sunlight
to reach our world.
8. Stars are celestial objects which emit heat and light on their own.
They also produce ultraviolet rays, x-rays, and many other forms of
radiation.
Stars are mainly composed of hot gases, like hydrogen and helium,
along with a superheated state of matter called plasma.
Plasma is an ionized gas where electrons are ripped away from the
atoms forming a superheated gas.
WHAT IS A STAR?
12. THE COLORS OF STARS
The colors of the stars indicate their surface temperatures.
There are five star colors: blue, white, yellow, orange, and
red.
13. Brightness
Apparent brightness is the rate at which a star's
radiated energy reaches an observer on Earth.
Apparent brightness depends on both luminosity and
distance.
A large star shines brighter than a small star.
The sun is the brightest star on earth because it is the
closest star to us.
14. Giant and Supergiant Stars
Giant and supergiant stars can be both young and very old
stars. These types of stars are several times bigger than our Sun,
often cooler, but brighter than our Sun. Some of them are;
• blue giants,
• red giants,
• red super giants, and
• blue super giants.
TYPES OF STAR
15. TYPES OF STAR
Main Sequence Stars
Main-sequence stars are stars similar to our Sun. They
convert hydrogen to helium in their cores, and the majority of the
stars are in this classification, including;
• White dwarf stars,
• Yellow dwarf stars, and
• Red dwarf stars.
16. Color and Surface temperature of selected stars
Stars color Surface temperature in Celsius
Sun Yellow 5,700
Proxima Centauri Red 2,300
Epsilon Iridami Orange 4,600
Vega White 9,900
Sirius White 10,000
Alnilam Blue 27,000
17. SIZE
White dwarf stars are a bit bigger often similar
in size to our planet Earth. The largest
supergiant stars can be more than 1500 times
larger than our Sun.
Red giant star and Red super giant star
18. Mass In general the more massive a star is the hotter
its surface
20. A group of stars that appear to
form a pattern or picture in the
night sky.
21.
22. •There are 88 constellations in the sky
•The largest constellation is ‘Hydra’
•The Greeks were the first to name the
constellations
•The smallest constellation is ‘Crux’
•Constellations change positions throughout the
year
Here are 10 facts about constellations
23. Facts about Constellation
•42 constellations are named after animals
•There is one star that doesn’t move in the sky
•People used the constellations to navigate in
ancient times
•The easiest constellation to find is Orion
•The constellations move from East to West
24. • The largest constellation is ‘Hydra’
• Hydra is named after the mythological giant snake. It extends a long
way across the sky and covers the most area out of any other
constellations in the sky.
• Unfortunately, Hydra is only visible on certain parts on Earth. In North
America. it can only be seen from Alaska and Northern Canada. In
Europe, it can only be seen in some Scandinavian countries like
Finland and Sweden.
Hydra
25. • The smallest constellation is ‘Crux’
• We don’t know who named this one but they definitely didn’t think
too much about it. The constellation Crux, meaning “the cross” is only
made of 4 stars in the shape of, well…a cross.
• Due to its position in the sky, Crux is mostly visible on Earth’s
southern hemisphere. In the U.S. it is only visible for short periods of
time and only in southern states like Texas.
Crux
26. • While all the stars are constantly changing positions in the
sky, there is one that stays almost still all the time.
• This star is named Polaris, but it is also known as the North
Star. It is part of the “little bear” constellation (Ursa Minor).
• This curious thing happens because the North Star is almost
perfectly aligned with Earth’s axis.
There is one star that doesn’t move in the sky
27.
28. ORION
Orion is one of the most
beautiful and striking
constellations in the whole
night sky. Furthermore, it is
located on the celestial
equator meaning it can be
viewed from all across the
Earth.
29. Evaluation:
Answer the following questions briefly.
What is a star?
What is Constellation?
What is the purpose of constellation?
Enumeration
1-7 Different types of stars
8-12 Colors of the stars
13-15 Hot gases make up the majority of stars
30. Answers:
Enumeration:
1. White dwarf stars
2. Yellow dwarf stars
3. Red dwarf stars
4. Blue giants
5. Red giants
6. Blue super giants
7. Red super giants.
8. Blue
9. White
10. Yellow
11. Orange
12. Red
13. Hydrogen
14. Helium
15. Plasma
31. Answers:
Enumeration:
1. White dwarf stars
2. Yellow dwarf stars
3. Red dwarf stars
4. Blue giants
5. Red giants
6. Blue super giants
7. Red super giants.
8. Blue
9. White
10. Yellow
11. Orange
12. Red
13. Hydrogen
14. Helium
15. Plasma
